New Functional Additive in Polymers

ABSTRACT

New functional additive in polymers comprised of micronized diatomite filler product, methods of producing the new functional additive in polymers, and methods of use thereof are provided. The new functional additive in polymers has, for example, a small median particle size (for example, less than 10 microns) and a small top particle size (for example, less than 20 microns), and a high blue light brightness (for example, higher than 84). The new functional additive in polymers may be used in a variety of applications such as reinforcement filler in polymers and anti-block filler in plastic films.

TECHNICAL FIELD

This invention relates to a new functional additive in polymers based onmicronized diatomite product, which is useful in various polymerapplications.

BACKGROUND ART

Throughout this application, various publications, patents, andpublished patent applications are referred to by an identifyingcitation; full citations for these documents may be found at the end ofthe specification. The disclosure of the publications, patents, andpublished patent specifications referred in this application are herebyincorporated by reference into the present disclosure.

Thermoplastic materials are those which soften under the action of heatand harden again to their original characteristics on cooling, that is,the heating-cooling cycle is fully reversible. By conventionaldefinition, thermoplastics are straight and branched linear chainorganic polymers with a molecular bond. Examples of well-knownthermoplastics include products of acrylonitrile butadiene styrene(ABS), styrene acrylonitrile (SAN), acrylate styrene acrylonitrile(ASA), methacrylate butadiene styrene (MBS). Also included are polymersof formaldehyde, known as acetals; polymers of methyl methacrylate,known as acrylic plastics; polymers of monomeric styrene, known aspolystyrenes; polymers of fluorinated monomers, known as fluorocarbons;polymers of amide chains, known as nylons; polymers of paraffins andolefins, known as polyethylenes, polypropylenes, and polyolefins;polymers composed of repeating bisphenol and carbonate groups, known aspolycarbonates; polymers of terephthalates, known as polyesters;polymers of bisphenol and dicarboxylic acids, known as polyarylates; andpolymers of vinyl chlorides, known as polyvinyl chlorides (PVC). Highperformance thermoplastics have extraordinary properties, for example,polyphenylene sulfide (PPS), which has exceptionally high strength andrigidity; polyether ketone (PEK), polyether ether ketone (PEEK),polyamide imide (PAI), which have very high strength and rigidity, aswell as exceptional heat resistance; and polyetherimide (PEI), which hasinherent flame resistance. Unusual thermoplastics include ionomers,i.e., copolymers of ethylene and methacrylic acid that have ionic ratherthan covalent crosslinking which results in behavior resembling that ofthermoset plastics in their operating range; polyvinylcarbazole, whichhas unique electrical properties; and polymers of isobutylene, known aspolyisobutylenes, which are viscous at room temperature.

Thermoset plastics are synthetic resins that are permanently changedupon thermal curing, that is, they solidify into an infusible state sothat they do not soften and become plastic again upon subsequentheating. However, certain thermoset plastics may exhibit thermoplasticbehavior over a limited portion of their useful application ranges, andare similarly useful as matrix components of the present invention. Sometypes of thermoset plastics, especially certain polyesters and epoxides,are capable of cold curing at room temperature. Thermoset plasticsinclude alkyds, phenolics, epoxides, aminos (including urea-formaldehydeand melamine-formaldehyde), polyimides, and some silicon plastics.

Mineral fillers have been added to thermoplastics and thermosets toimprove their properties including tensile strength, heat distortiontemperature, and modulus. Besides improvement on the properties, fillersalso reduce costs since the filled thermoplastics are sold in evenlarger volumes than neat thermoplastics.

The adhesion of the polymer matrix onto the filler particles has strongimpact on the reinforcement. The mechanical properties can be furtherenhanced if the polymer matrix adheres to the filler particle surfacethrough chemical coupling agents such as silanes.

Anti-block products are normally used in the plastic films to lessen theadhesion or blocking of the plastic film surface. This can be achievedby slightly roughening the film surface through surface treatment withwax/polymers or by adding anti-block filler products into the plasticfilms. Commercial anti-block filler products include synthetic silica,natural silica (such as diatomaceous earth), and other mineral productssuch as talc, calcium carbonate, and nepheline syenite. These additivesare intended to produce microscopic roughness on the surface of the filmto minimize the flat contact between adjacent layers, i.e., to preventindividual layers from sticking to one another or blocking. Althoughsynthetic silica has good anti-block performance and optical properties,the high cost limits its applications in the plastic films. Diatomaceousearth is an effective anti-block agent with moderate cost. Theanti-block performance of other mineral products such as talc, calciumcarbonate, and nepheline syenite are not as effective compared todiatomaceous earth product.

Particle size has strong effect on filler performance. For reinforcementin polymers, classic theory suggests that a top size of below 10 micronsgives the best impact strength as particles larger than this providecrack nucleation points within the polymer matrix. The anti-blockperformance and the film physical properties also strongly depend on theparticle size of the filler products.

Color is also important for a filler in any application, especiallywhere color of the end product is important. Whiter filler products withhigh blue light brightness normally have greater utility, as they can beused in all colored and white products and, relative to non-whitefillers, improved plastic film optical properties. For these reasons,micronized diatomite products with high blue light brightness are oftendesirable.

There is a need for a new functional additives in polymers based onmicronized diatomite product with fine particle size and high bluelightness brightness for various filler applications in polymers.

Paris Convention Article 11 Disclosure

Certain elements of the invention disclosed herein were placed ondisplay at The 17^(th) Industrial Minerals International Congress heldin Barcelona, Spain on Mar. 28-30, 2004.

SUMMARY OF THE INVENTION

A new functional additive in polymers employs micronized diatomitehaving a median particle size less than 10 microns and a top particlesize less than 20 microns. In alternative embodiments, the medianparticle size and top particle size are respectively less than 8 micronsand less than 18 microns, less than 6 microns and less than 16 microns,less than 4 microns and less than 13 microns, and, less than 3 micronsand less than 10 microns.

The new functional additive in polymers has a blue light brightnessgreater than 80 and in alternative embodiments has a blue lightbrightness greater than 82, 84, 86, 88, and 90.

The new functional additive in polymers in certain embodiments providesa reinforcing effect in thermoplastics such as Nylon.

The new functional additive in polymers in other embodiments can be usedas functional filler in paints, coatings and papers.

Another aspect of the present invention employs a method of preparingthe micronized diatomite filler product using jet mill equipment.

Still another aspect of the present invention employs a method ofpreparing micronized diatomite filler product using stirred media millequipment.

Still another aspect of the present invention employs a method ofpreparing micronized diatomite filler product using ball mill equipment.

Still another aspect of the present invention employs a method ofpreparing micronized diatomite filler product using ball mill combinedwith air classifier.

Still another aspect of the present invention employs a method ofpreparing micronized diatomite filler product using Mikro-ACM® airclassifying mill (Hosokawa Micron Powder Systems, Summit, N.J.).

Still another aspect of the present invention employs a method ofpreparing surface modified micronized diatomite filler product bysilanization. In one embodiment, the silanization is induced using“in-situ” addition of silane during the milling stage. In an exemplaryembodiment, the surface of the product is modified withgamma-aminopropyltriethoxy silane.

In certain embodiments, the silanization increases the hydrophobicproperties of the additive, for example using Dimethyldichlorosilane orHexadimethylsilazane. In alternative embodiments, the silanizationincreases the hydrophilic properties of the additive, for example usingaminopropyltriethoxysilane.

MODES FOR CARRYING OUT THE INVENTION

Provided is a new additive in polymers based on micronized diatomitefiller product having very fine particle size. In one embodiment, thereis provided an expanded diatomite product having a very fine particlesize (for example, less than 3 microns).

In a further embodiment, the micronized diatomite filler product ischaracterized by high blue light brightness (for example, greater than80). The micronized diatomite filler product advantageously has veryfine particle size and high blue light brightness, thereby permittingmuch greater utility in polymer filler applications.

Diatomite products are obtained from diatomaceous earth (also known askieselguhr), which is a sediment enriched in the siliceous frustules,i.e., shells, of diatoms. Diatoms are a diverse array of microscopic,single-celled golden brown algae of the class Bacillariophyceae, inwhich the cytoplasm is contained within ornate siliceous frustules ofvaried and intricate structure. These frustules are sufficiently durableto retain much of their porous structure virtually intact through longperiods of geologic time when preserved in conditions that maintainchemical equilibrium. Currently, diatomite products may be manufacturedby a variety of methods and from numerous resources, offering diversityin physical and chemical characteristics. Recent reviews (Breese, 1994;Engh, 1994) provide particularly useful introductions to the propertiesand uses of diatomite.

In a typical conventional method of preparing commercial diatomiteproducts, crude ores of diatomaceous earth are crushed to a size thatcan be further reduced by milling, air classified, and dried in afurnace in air with subsequent air classification to achieve a desiredproduct permeability, thus forming a dried product, commonly referred toas “natural” diatomite.

In another conventional method, a natural product can be sintered in air(commonly called calcining) at temperatures typically ranging from 1800to 2000° F. (i.e., 1000 to 1100° C.), followed by air classification.This method achieves more permeable products, but is usually accompaniedby partial conversion of amorphous silica (the natural phase of silicaof diatomaceous earth ores) to cristobalite, which is a tetragonal formof crystalline silica. Products made by this method typically havecristobalite contents ranging from 5 to 40% by weight.

In another conventional method, a dried product can also be furthersintered in air with the addition of a small quantity of flux (commonlycalled flux calcining) at temperatures typically ranging from 1800 to2100° F. (i.e., 1000 to 1150° C.), followed by air classification. Thismethod achieves still more permeable products, but usually with evengreater conversion of amorphous silica to cristobalite, which istypically present in the range of 20 to 75% by weight. The most commonlyused fluxes include soda ash (i.e., sodium carbonate, Na₂CO₃) and rocksalt i.e., sodium chloride, NaCl), although many other fluxes,particularly salts of the alkali metals i.e., Group IA of the periodictable) are useful.

The typical chemical compositions for natural, calcined and fluxcalcined diatomite products are listed in the Table 1.

TABLE 1 Constituent, % Natural Product Calcined Product Flux CalcinedProduct Al₂O₃ 4.06 3.54 3.63 Fe₂O₃ 1.54 1.45 1.40 CaO 0.91 0.69 0.71Na₂O 0.53 0.59 3.86 P₂O₅ 0.27 0.18 0.17 MgO 0.67 0.54 0.60 K₂O 0.67 0.620.62 SiO₂ 89.90 90.80 87.90 TiO₂ 0.21 0.20 0.21 LOI* 1.24 1.39 0.90Total 100.00 100.00 100.00 *Lost on ignition.

The high temperatures involved in the conventional methods of sinteringdiatomite products usually result in reduced surface area, enlargementof pores, increased wet density, and changes in impurity solubility, inaddition to the expected silica phase change from the amorphous state tocristobalite.

Other methods have been described in detail for processing diatomite andpreparing products made from diatomite. Much effort to improve low gradediatomaceous earths into higher grade ores has resulted in diatomiteproducts essentially equivalent in their overall quality to commercialproducts obtained from naturally better ores. Examples of such workincludes that of Norman and Ralston (1940), Bartuska and Kalina (1968a,1968b), Visman and Picard (1972), Tarhanic and Kortisova (1979), Xiao(1987), Li (1989), Liang (1990), Zhong et al. (1991), Brozek et al.(1992), Wang (1992), Cai et al. (1992), and Videnov et al. (1993).Several diatomite products that have been prepared with a singleproperty targeted for improvement, for example, reduced total iron orsoluble iron concentration, have been reported by Thomson and Barr(1907), Barr (1907), Vereinigte (1913, 1928), Koech (1927), Swallen(1950), Suzuki and Tomizawa (1971), Bradley and McAdam (1979), Nielsenand Vogelsang (1979), Heyse and Feigl (1980), and Mitsui et al. (1989).A diatomite product made by Baly (1939) had low organic matter, andCodolini (1953), Pesce (1955, 1959), Martin and Goodbue (1968), and Munn(1970) made diatomite products with relatively high brightness. Adiatomite product made by Enzinger (1901) reduced conventionalsolubility at that time. Diatomite products made by Bregar (1955),Gruder et al. (1958), and Nishamura (1958) were brighter, coupled with alower total iron concentration. A product made by Smith (1991a,b,c;1992a,b,c; 1993; 1994a,b) improved on the soluble multivalent cations ofa flux calcined diatomite product. Schuetz (1935), Filho and Mariz daVeiga (1980), Marcus and Creanga (1965), and Marcus (1967) also reportedmethods for making somewhat purer diatomite products. Dufour (1990,1993) describes a method for preparing diatomite products with lowcristobalite content. Shiuh (1997, 2003) describes methods for producingextremely pure diatomite products. Hessling (2004) disclosed a grindingmethod to produce ultra fine diatomite products.

The micronized diatomite filler product of the present invention hasvery fine particle size and high blue light brightness, therebypermitting much greater utility, particularly as filler products used asadditives in polymers.

Using methods disclosed herein, commercially available equipmentdesigned to mill minerals of normal densities may be used to milldiatomite to thereby produce the micronized diatomite filler products ofthe present invention. The products so made are superior in manyapplications to existing products, and the production process iseconomically attractive because a high yield of the desired product isobtained.

In one embodiment, the micronized diatomite filler product is providedwith a median particle size less than 10 microns and a top particle sizeless than 20 microns. In another embodiment, the median particle size isless than 5 microns and the top particle size less than 14 microns, forexample, the median particle size less than 4 microns and the topparticle size less than 13 micron, the median particle size less than 3microns and the top particle size less than 10 micron.

In another embodiment, the micronized diatomite filler product isfurther characterized by having a blue light brightness greater than 80;greater than 82; greater than 83; or in one preferred embodiment,greater than 85.

In another embodiment, the micronized diatomite filler product isfurther characterized by surface modification usinggamma-aminopropyltriethoxy silane.

A. Methods for Preparing the New Functional Additives in Polymer Basedon Micronized Diatomite Filler Product

As described above, the new functional additive in polymers based on themicronized diatomite filler product has a defined particle size andother unique physical properties. The micronized diatomite fillerproduct can be prepared by several methods.

One preferred method of preparing the new functional additive inpolymers of the present invention is by milling on a fluidized bed jetmill.

Another preferred method of preparing the new functional additive inpolymers of the present invention is by milling on a Mikro-ACM® airclassifying mill.

Another preferred method of preparing the new functional additive inpolymers of the present invention is by milling on a stirred media millwith ceramic lining.

Another preferred method of preparing the new functional additive inpolymers of the present invention is by milling on a ball mill combinedwith an air classifier.

Commercially available natural, calcined and flux calcined diatomiteproducts may be used as feed materials. For examples, Hyflo®, Celite®545, Celite® 281 and Primsil® 30A (Hyflo®, Celite® and Primsil® aretrademarks of Celite Corporation, Santa Barbara, Calif.) are useful feedmaterials. In some cases, special feed materials can be prepared usingflux calcination.

The new functional additive in polymers is further modified inalternative embodiments to enhance its performance in specificapplications. For example, surfaces ob the additive are treated withamino-silane coupling agent to further enhance the reinforcementperformance in thermoplastics and thermosets.

The new functional additive in polymers is also alternatively modifiedby other silanization to render the surfaces either more hydrophobic orhydrophilic using the methods appropriate for silicate minerals(Moreland, 1975; Sample, 1981). For example, the micronized diatomitefiller product can be placed in a plastic vessel, and a small quantityof dimethyldichlorosilane (i.e., SiCl₂(CH₃)₂) or hexadimethylsilazane(i.e., (CH₃)₃Si—NH—Si(CH₃)₃) added to the vessel. Reaction is allowed totake place at the surface in the vapor phase over a 24 hr period,resulting in more hydrophobic products. Such products have applicationsin compositions used in chromatography, for example, and also when usedin conjunction with other hydrophobic materials for improved mechanicalperformance, for example, in applications involving hydrocarbons andoils, and also to provide reinforcement in plastics and other polymers.

Similarly, the new functional additive in polymers can be reacted, forexample, by suspending it in a solution containing 10% (w/v)aminopropyltriethoxysilane (i.e., C₉H₂₃NO₃Si) in water, refluxing at 70°C. for 3 hr, filtering the mixture, and drying the remaining solids toobtain more hydrophilic products. Such products have applications incompositions used in chromatography, for example, especially when usedin conjunction with aqueous systems for improved mechanical performance,and to permit further derivatization of the product, having convertedterminal hydroxyl (i.e., —OH) functional groups at the surface of thediatomite product with controlled particle size distribution toaminopropyl groups (i.e., —(CH₂)₃NH₂). The hydrophilic (e.g., silanized)modified the micronized diatomite filler product can be further reactedto bind an organic compound, for example, a protein; the improveddiatomite product with controlled particle size distribution therebyserves as a support for the immobilization of the organic compound. Somodified, the product has utility in applications such as affinitychromatography and biochemical purification.

The surfaces of the new functional additive in polymers is also etchedin certain embodiments with etchants appropriate for glasses, including,but not limited to, hydrofluoric acid (i.e., HF), ammonium bifluoride(i.e., NH₄F.HF), sodium hydroxide (i.e., NaOH), fluorine, ammonia,ammonium hydroxide, or phosphoric acid. Surface etching may enhancesubsequent treatment processes; for example, etching may increase thenumber of terminal hydroxyl groups, which in turn may subsequently reactwith various silanes.

A number of other reactions pertaining to the surfaces of glasses havebeen previously described (Hermanson, 1992). However, derivatizations ofthe new functional additive in polymers which offer specific propertiesyield products with improved efficacy.

Modifications and variations of the invention as hereinbefore set forthcan be made without departing from the spirit and scope thereof.

B. Methods for Characterizing the Micronized Diatomite Filler Product 1.Particle Size Distribution

The particle size distribution of samples is determined in accordancewith the phenomenon of scattered light from a laser beam projectedthrough a stream of particles. The amount and direction of lightscattered by the particles is measured by an optical detector array andthen analyzed by a microcomputer which calculates the size distributionof the particles in the sample stream. Data reported is collected, forexample, on a Leeds and Northrup Microtrac X100 laser particle sizeanalyzer (Leeds and Northrup, North Wales, Pa.). This instrument candetermine particle size distribution over a particle size range from0.12 to 704 microns. Median particle size (d₅₀) is defined as that sizefor which 50 percent of the volume that is smaller than the indicatedsize. The top size (d₉₀) is defined as that size for which 90 percent ofthe volume that is smaller than the indicated size

The new functional additive in polymers in one embodiment has a medianparticle size less than 10 microns (usually in the range of from 8 to 10microns) and a top particle size less than 20 microns (usually in therange of from 16 to 20 microns). In another embodiment, the medianparticle size is less than 8 microns (for example, in the range of 5 to8 microns) and a top particle size less than 18 microns (usually in therange of from 16 to 20 microns), the median particle size is less than 5microns and a top particle size less than 14 microns, the medianparticle size is less than 4 microns and a top particle size less than13 microns, the median particle size is less than 3 micron and a topparticle size less than 10 microns.

2. Blue Light Brightness

The preferred method for determining the blue light brightness of thesamples in the present invention uses calculation from Hunter scalecolor data collected on a Spectro/plus Spectrophotometer (Color andAppearance Technology, Inc., Princeton, N.J.). A krypton-filledincandescent lamp is used as the light source. The instrument iscalibrated according to the manufacturer's instructions using a highlypolished black glass standard and a factory calibrated white opal glassstandard. A plastic plate having a depressing machined into it is filledwith sample, which is then compressed with a smooth-faced plate using acircular pressing motion. The smooth-faced plate is carefully removed toinsure an even, unmarred surface. The sample is then placed under theinstrument's sample aperture for the measurements.

The new functional additive in polymers for example has a blue lightbrightness greater than 80 (e.g., in the range from 80 to 85); has ablue light brightness greater than 85 (e.g., in the range from 85 to90), or has a blue light brightness greater than 90 (e.g., in the rangefrom 90 to 93).

3. Oil Absorption

The oil absorption capacity of the samples in the present invention isdetermined on a weight basis. 5 or 10 grams of the sample is placed in a300 ml ceramic casserole. Linseed oil from a 50 ml glass burette is thenadded to the sample at the rate of 1 drop per second. During addition ofoil, the mixture is stirred using a spatula so that each drop of oilfalls on a dry position of the sample. As absorption of oil progresses,the lumps of paste form larger lumps and the oil addition rate should bedecreased at this point. The absorption reaches to the end point whenall of the dry sample is wet and picked up. The volume of the oil usedis then recorded and the oil absorption in weight percentage can thus becalculated:

Oil absorption (in weight percentage)=(volume of oil used (ml)×specificgravity of oil)/(weight of sample (g))×100

4. Reinforcement Performance Tests in Nylon

a. Formulation

Nylon was chosen as the polymer to evaluate the new functional additivein polymers for thermoplastics since Nylon uses relatively high valuefillers and has a low melt viscosity, making it more likely to penetrateand wet the test products. Nylon (PA 6), grade Akulon F-236-D from DSM(DSM Engineering Plastics, Sittard, The Netherlands) was chosen in thisstudy due to its significantly lower processing temperature. The mostcommonly used silane for nylon applications, gamma-aminopropyltriethoxysilane was chosen as the silane modifier.

The addition levels chosen for the test fillers were determined by twofactors; the small amount of sample available in some cases and the oilabsorption values. These varied from 20-30% by weight (10-20% byvolume). All the test fillers were evaluated with and without surfacetreatment with a silane coupling agent, suitable for nylon(amino-silane). The silane level used was based on knowledge of thecovering power of the silane and the fillers specific surface area, andvaried from 0.4-4% by weight. When silane was used, coating was carriedout by what is known as the “in-situ” method, (i.e. during compoundingitself). This method is sufficient to show whether silane is effective,but is usually not the most efficient way of filler treatment. It alsointroduces traces of alcohol into the formulation, which is not alwaysdesirable. The silane coating was carried out with pre-dried fillers.

b. Compounding and Testing

As is usual with nylon compounding, all the materials were pre-dried.Where the test fillers were coated with silane, this was achieved bywetting the polymer granules with the silane prior to mixing with thefiller powder. Any coating then takes place in the compounder.

Compounding was carried out using a Beetol twin-screw compounder. Thepolymer granules and filler powder were pre-mixed and fed from a singlehopper. The melt was extruded in a double strand, which was cooled in awater bath and then pelletised. After drying, the pellets were injectionmoulded into the appropriate test pieces using a standard injectionmoulding machine. The moulded specimens were equilibrated with roomconditions for one week before testing. Mechanical properties such asmodulus, tensile strength, impact strength were then measured.

C. Methods of Using the Micronized Diatomite Filler Product

The new functional additive in polymers can be used in a manneranalogous to the currently available anti-block filler products inplastic film applications.

Certain applications may gain additional benefit from using the newfunctional additive in polymers that has been modified or derivatized,for example, by leaching with acid or complexing agents, by etching, bysilanization, or by coupling organic molecules to a silanizedfunctionality.

The most common method of adding the new functional additive in polymersto prepare a filled material is to blend it into a mixture at aconcentration needed to impart the desired level of a property. Forexample, to reinforce nylon, the micronized diatomite filler product maybe added to a controlled-temperature twin-screw extruder to whichunfilled nylon is being fed and made molten. The new functional additivein polymers is fed into the extruder through a hopper and uniformlyblends in to the nylon. The mixture emerges from the extruder and iscooled. Then, for example, the mixture can be further compression moldedor injection molded into useful shapes, and the molded pieces of fillednylon will be suitably reinforced compared with the unfilled nylon.

The new functional additive in polymers of the present invention can beused as a functional filler practically as a anti-block filler.Functional fillers are typically added, that is, “compounded,” to othersubstances to make a material mixture that may commonly be referred toas “filled.” The means of compounding usually allows one or morespecific functional properties to be imparted to the filled material.These functional properties are often physical in nature, and mayinvolve various mechanical or optical effects. Occasionally, chemicalfunctionality is imparted, and this may also alter electricalproperties. The new functional additive in polymers is effective whencompounded in filled materials so as to impart the functionality of theimproved diatomite product to the filled material.

Examples of other filler applications include use of the new functionaladditive in polymers distribution as a flatting agent or as an aid toimprove scrubbability in paints and coatings; as an anti-block agent inpolymers, such as polyethylene or polypropylene film; as a functionalfiller in paper, including as a drainage aid and in stickiespacification in paper manufacture; as a reinforcing agent in plastics,including nylon, polypropylene, phenolics and brake pad manufacture; andas a filler for adhesive, sealant, and joint compounds.

The new functional additive in polymers is also useful in abrasive,polishing, buffing, or cleansing formulations, wherein it may impart anabrasive property. Further, the new functional additive in polymers isuseful in ceramics and ceramic mixtures, including tile, asphalt,concrete, mortar, plaster, stucco, grout, and aggregate, especially todecrease the density of these materials. The new functional additive inpolymers may be applied to other architectural products, includingroofing shingles or sheets, architectural siding, flooring, oracoustical tile with similar efficacy.

The aforementioned applications describe the utility of the micronizeddiatomite filler product, but many other applications may be envisionedfor the micronized diatomite filler product.

EXAMPLES

The new functional additive in polymers based on micronized diatomitefiller product of the present invention and methods for theirpreparation are described in the following examples, which are offeredby way of illustration and not by way of limitation.

Particle size data were collected on a Leeds and Northrup Microtrac X100laser particle size analyzer (Leeds and Northrup, North Wales, Pa.).

Examples 1 to 9 were prepared using a pilot scale Alpine® AFG 400Fluidized Bed Jet Mill (Hosokawa Micron Powder Systems, Summit, N.J.). Acommercially available diatomite product, Hyflo® was used as the feedmaterial for Examples 1 to 5. The feed materials for Examples 6 and 7were flux calcined diatomite using the crude from the Lompoc, Calif. andQuincy, Wash. deposits.

Examples 10 to 14 were prepared using a pilot scale Mikro-ACM® AirClassifying Mill Model 10 System (Hosokawa Micron Powder Systems,Summit, N.J.). Commercially available diatomite products, Celite® 281and Hyflo®, were used as the feed material for Examples 12 and 14. Thefeed materials for Examples 10, 11, and 13 were flux calacined diatomiteusing the crude from the Lompoc, Calif. and Quincy, Wash. deposits.

Example 15 was prepared using a pilot scale ceramic lined 50-SDGAttritor stirred media mill (Union Process, Akron, Ohio). A commerciallyavailable diatomite product, Hyflo®, was used as the feed material.

Examples 16, 17, 18, 21, 22 and 23 were prepared using a NETZSCH CONDUX®Conjet High Density Bed Jet Mill (NETZSCH-Feinmahltechnik GmbH, Hanau,Germany). Commercially available diatomite products, Primisil® 30A andCelite® 281, were used as the feed materials.

Examples 19 and 20 were prepared using an Alpine® ANR agitator ball mill(HOSOKAWA ALPINE Aktiengesellschaft & Co. OHG, Augsburg, Germany) and anAlpine® LK80/32 ball mill (HOSOKAWA ALPINE Aktiengesellschaft & Co. OHG,Augsburg, Germany) respectively. A commercially available diatomiteproduct, Celite® 281, was used as the feed material.

Examples 24 and 25 were prepared using an Alpine® LK80/32 ball mill with“in-situ” addition of gamma-aminopropyltriethoxy silane. A commerciallyavailable diatomite product, Celite® 281, was used as the feed material.It was observed that the addition of the silane at the milling stage ofthe production process had facilitated the milling process and hadreplaced the grinding aid that was conventionally used in suchapplications to improve the production rate.

Tests to determine the particle size distribution, blue lightbrightness, and oil absorption were carried out according to the methodsdescribed above. The results for the new functional additive in polymersbased on micronized diatomite filler product are shown in Table 2. Thenew functional additive in polymers based on micronized diatomite fillerproduct of these examples had a median particle size less than 10microns and a top particle size less than 20 microns, blue lightbrightness more than 80. As a result of the microstructural complexityof diatomite, the oil absorption of the new functional additive inpolymers is generally greater than what would be expected to reinforcepolymers.

TABLE 2 Production d₅₀ d₉₀ Blue Light Oil Absorption Examples FeedOrigin Method (μm) (μm) Brightness (weight %) Example 1 Hyflo ® Almeria,Mexico Flux Calcined 9.11 18.23 92.55 82 Example 2 Hyflo ® Almeria,Mexico Flux Calcined 5.91 12.12 91.23 76 Example 3 Hyflo ® Almeria,Mexico Flux Calcined 4.27 9.12 91.51 82 Example 4 Hyflo ® Almeria,Mexico Flux Calcined 3.36 7.52 91.86 Example 5 Hyflo ® Almeria, MexicoFlux Calcined 2.55 5.04 93.34 Example 6 Special Feed Lompoc, CA FluxCalcined 5.82 13.56 91.05 78 Example 7 Special Feed Quincy, WA FluxCalcined 8.50 19.30 87.20 63 Example 8 Celite ® 545 Linjinag, China FluxCalcined 7.19 16.63 87.32 45 Example 9 Celite ® 545 Linjinag, China FluxCalcined 6.49 13.70 87.02 45 Example 10 Special Feed Lompoc, CA FluxCalcined 6.37 15.66 83.82 65 Example 11 Special Feed Lompoc, CA FluxCalcined 5.73 12.56 83.50 60 Example 12 Hyflo ® Almeria, Mexico FluxCalcined 8.06 16.15 87.53 74 Example 13 Special Feed Quincy, WA FluxCalcined 8.08 17.35 80.88 Example 14 Celite ® 281 Lompoc, CA FluxCalcined 7.76 17.87 87.88 88 Example 15 Hyflo ® Almeria, Mexico FluxCalcined 3.11 12.11 92.75 48 Example 16 Celite ® 400TC Almeria, MexicoNatural 2 Example 17 Primsil ® 30A Alicante, Spain Natural 2 4 Example18 Celite ® 281 Alicante, Spain Flux Calcined 1.96 7.05 Example 19Celite ® 281 Alicante, Spain Flux Calcined 2 Example 20 Celite ® 281Alicante, Spain Flux Calcined 2 Example 21 Celite ® 281 Lompoc, CA FluxCalcined 2 Example 22 Celite ® 281 Quincy, WA Flux Calcined 2 Example 23Celite ® 281 Almeria, Mexico Flux Calcined 2 Example 24 Celite ® 281Alicante, Spain Flux Calcined 2 Example 25 Celite ® 281 Alicante, SpainFlux Calcined 2

The performance of the new functional additive in polymers as areinforcing filler for thermoplastics was evaluated in Nylonformulation. Two standard commercial nylon filler products, calcinedclay Polarite 102 A (Imerys, Paris, France) and glass beads SpheriglassCPO₃ (Potters Industries Inc., Valley Forge, Pa.), were used ascontrols. Polarite 102 A was pre-treated with an amino-silane couplingagent by the manufacturers (level unknown). These two fillers were usedat 35 percent by weight. Because of the density differences, the volumepercent loadings were closer than the weight percent loadings wouldsuggest. The physical properties of these products are listed in Table3.

TABLE 3 Polarite 102 A Spheriglass CP03 Physical Properties (CalcinedClay) (Glass Beads) Example 16 Example 17 Example 18 Surface Area (m²/g)8.5 <1 30 10 2 d₅₀ (micron) 2 10-20 2 2 2 Specific Gravity 2.6 2.5 2.12.1 2.1 Oil Absorption Not available Not available 240 130 120 Hardness(Moh) 4 Not available 4-5 4-5 4-5 Refractive Index 1.6 1.5 1.45 1.451.45? Water Content (%) <0.5 <0.5% >5.5% >4% 1.1%

Table 4 shows a qualitative description on the color. The silanetreatment only had a small effect on color.

TABLE 4 Product Color Spheriglass CP03 (glass Beads) Dark but quitetranslucent Polarite 102 A (calcined clay) Dark, but not verytranslucent Example 16 Grey, trace of translucency Example 17 Lightgrey, not very translucent Example 18 Light grey, some translucency

A rough estimate was made from the weight of injection mouldedspecimens, using the unfilled nylon as the standard (specificgravity=1.13). The results are listed in Table 5.

TABLE 5 Product Density (g/cm³) Unfilled PA 1.13 Spheriglass CP03 (glassbeads, 35% by 1.43 weight nominal) Polarite 102 A (calcined clay, 35% by1.40 weight nominal) Example 16 (20% by weight nominal) 1.24 Example 17(30% by weight nominal) 1.29 Example 18 (30% by weight nominal) 1.33

Powdered fillers tend to separate in the feed hopper and some oftenremains on the walls. This can result in lower filler levels than aimedfor when small amounts are compounded. Some of the compounds werechecked by ashing test to confirm the actual loading level. For example,the actual loading level for Polarite 102 A (calcined clay) was 32.2percent by weight as compared to the nominal 35 percent by weight. Atthe nominal 30 percent by weight, the actual loading level for Example17 and Example 18 were 27.7% and 26.4%, respectively. This indicates theactual loading levels are consistent with nominal loading levels.

Table 6 shows the test results on the mechanical properties of theproducts. The test results for the controls are in line with publisheddata. As expected, both glass beads and calcined clay significantlyincrease the modulus and the glass beads give a lower tensile and impactstrength than the calcined clay, due to their larger particle size.

There appears to be a small reduction in tensile modulus. The cause ofthis is uncertain, but it may be due to alcohol release from the silanein the “in-situ” method. Modulus is also a key property and the levelsachieved are generally slightly less than for the clay (which, assumingthat the loadings were correct was at a slightly higher filler level).The impact strength is also a very important property and the highlevels obtainable could be very valuable. The performance of Example 16is less clear. Given the low loading used, the performance of the samplewithout silane is very reasonable. There was an apparent large loss intensile modulus on silane treatment, but not in the more reliableflexural modulus. Much more silane was used with this sample (because ofthe specific surface area) and this lends support to the view that thelower tensile modulus might be due to the use of the “in-situ” coatingmethod. To fully establish the potential for this material would needsome optimization of coating method and level and examination of higherfiller loadings.

TABLE 6 Impact Tensile Strength Level Level Modulus (Mpa) Strength(Un-notched, Filler Product wt % v % Tensile Flexural (Mpa) KJ/m²) None0 0 2750 1420 67 >100 Spheriglass 35 19 5265 2640 58 22 CP03 Glass BeadsPolarite 102 A 35 19 5700 2990 79 62 Calcined Clay Example 16 20 11 45502450 70 35 Example 16 + 20 11 3750 2430 78 67 4% SILANE Example 17 30 185570 3020 70 25 Example 17 + 30 18 5095 2965 80 77 2% SILANE Example 1830 18 4900 2445 70 36 Example 18 + 30 18 4760 2465 72 >100 0.4% SILANE

The effect of top size of filler products on the performance in the DuPont PA6 was studied. Filler loading was a nominal 30% w/w unlessotherwise stated. A calcined clay Polarite 102A was used as the controlsample.

As shown in Table 7, reducing the top-cut does not seem to have a greateffect in the range studied, although the finest size was the only onein the present series to give all unbroken samples in the un-notchedimpact test. While all the classified samples have similar notchedimpact strengths, these are significantly higher than an unclassifiedExample 18 tested earlier. The Polarite results suggest that thisproperty may be giving higher results in the present series, so no firmconclusion about this can be drawn. It must also be pointed out that theunclassified Example 18 was not from the same batch as used for theclassification work (none of this was supplied from Alpine), andassessment of the effect of 499 batch to batch variation in compositionon filler performance is needed.

Existing theory has shown that particles over 10 microns is size have asignificant detrimental effect of such mechanical properties especiallyimpact resistance. However, the pore structure of diatomite gives thelarger particles the ability to act as a network of smaller objectswithin the polymer matrix. The addition of silane is critical to this asit draws the polymer into the complex diatomite structure. The additionof such a surface/interface modifier the wetting of the particles ismore complete and as such seen greater functionality.

TABLE 7 Yield Secant Flex Elongation Elongation Impact Strength StressModulus Modulus Yield Break (T KJ/m²) Examples (Mpa) (Mpa) (Mpa) (%) (%)Un-notched Notched Polarite 102 A 85.4 5912 3932 3.3 7.9 91.5 13.0Example 18 85.3 4632 nd 2.5 9.4 >100 9.3 Top Size 25 μm 86.5 5371 39273.9 4.9 94.5 14.0 Top Size 20 μm 85.9 5095 3905 5.2 7.9 93.0 14.8 TopSize 15 μm 88.7 4993 3936 4.6 6.7 >100 13.5

Table 8 displays the results on aging study. These results show quitegood agreement and no real evidence of ageing. Example 25 shows anapparent increase in notched impact over the previous test result, butas discussed above, this property may be reading higher in this seriesanyway. Example 25 compares well with the Polarite 102 A run in thecurrent series, but the present indications are that 2 micron materialcoated by the “in-situ” method is probably more effective.

TABLE 8 Yield Secant Flex Elongation Elongation Impact Strength FillerLoading Stress Modulus Modulus Yield Break (T KJ/m²) Level (wt %) (Mpa)(Mpa) (Mpa) (%) (%) Un-notched Notched Example 25 85.5 3537 n.d. 3.611.5 >100 9.3 (Milled with 0.6% A-1100 as the milling aid) ORIGINALExample 25 84.0 4857 3785 4.2 7.2 92.5 13.6 (Milled with 0.6% A-1100 asthe milling aid) SEVERAL WEEKS OLD

The performance of Example 18 in Nylon 66 was evaluated withamino-silane coatings from OSi (A-1100) and Dow Corning (6011) (Table9). As expected, they also show very close performance for the OSi andDow Corning silanes. There is an indication that too much silane may bedetrimental in this case, an effect not seen before. The performance atthe higher filler level (45%) is still encouraging.

TABLE 9 Yield Secant Elongation Elongation Impact Strength Silane LevelStress Modulus Yield Break (T KJ/m²) (A-1100) (Mpa) (Mpa) (%) (%)Un-notched Notched 30% and 0.3% 88.0 5887 4.1 6.7 >100 10.0 A1100 30%and 0.6% 89.1 5337 3.8 16.8 >100 14.3 A 1100 30% and 0.6% 88.0 5170 3.816.8 >100 13.4 Dow 6011 30% and 0.9% 90.2 5795 3.7 10.3 76.5 10.6 A 110045% and 0.6% 93.5 6320 4.0 5.3 75.5 13.0 A1100

Table 10 shows the results on three samples prepared from same Celite®281 feed but from different origin. It was tested at the 30% fillerlevel with and without silane addition. All the calcined diatomitesamples gave good results, with Example 22 from Quincy origin andExample 23 from Mexico origin giving especially good notched impactstrengths. Example 22 from Quincy origin also gave quite a goodperformance uncoated.

TABLE 10 Secant Elongation Elongation Impact Strength Silane Level YieldStress Modulus Yield Break (T KJ/m²) (A-1100) (Mpa) (Mpa) (%) (%)Un-notched Notched Example 21 85.9 5475 2.9 3.5 46.4 7.0 0% Example 2188.1 5308 8.3 11.1 >100 13.1 0.6% Example 23 85.3 5579 2.7 3.4 50.0 6.50% Example 23, 87.0 5592 5.8 15.8 >100 16.8 0.6% Example 22 87.3 50923.0 4.0 75.3 8.5 0% Example 22 87.3 5460 9.5 20.6 >100 15.4 0.6%

Table 11 demonstrates that the optimal coating level lies between arelative value of 2 and 3, this is surprising given that the theoreticalmonolayer value would be in the order of 6. This gives rise to aninteresting property of the material that there are obviously regions tothe complex silica structure that are not accessible to the coating orthat the surface chemistry is such that the coating does not bond. Thelow hydroxyl coverage of the diatomite surface due to its origin as anatural material is proving an advantage when it come to maximizing thesteric interaction of molecules at the filler polymer interface.

TABLE 11 Yield Secant Flex Elongation Elongation Impact Strength FillerLoading Stress Modulus Modulus Yield Break (T KJ/m²) Level (wt %) (Mpa)(Mpa) (Mpa) (%) (%) Notched 1 89.9 5192 4205 3.7 3.8 10.1 2 90.5 55744282 3.7 3.7 12.7 3 90.6 5907 3993 4.3 6.2 13.4 4 88.9 5502 3.4 5.8 13.4

Effect of milling method on the performance in Nylon 66 was studied(Table 12). Examples 19 and 20 were prepared using a ball milling and astirred media mill, respectively. Results for Example 18 with 0.6%silane prepared using a jet mill are also included for comparison. Theresults show that the ball/stirred media milled materials performs atleast as well as the jet milled product, and that the silane appears tofunction well, despite the milling aid. The ball/stirred media milledfillers would seem to be somewhat better than the jet milled whenuncoated, and to give a slightly lower modulus, but greater toughnesswhen silane treated.

TABLE 13 Example 18 Example 20 Example 19 Property No silane 0.6% silaneNo silane 0.6% silane 0.6% silane TENSILE YIELD 90 90.6 85.1 (1.1) 85.3(0.8) 89.1 (1.3) MPa SECANT 5764 5907 4746 (147) 4845 (408) 5377 (622)MODULUS MPa ELONGATION AT 1.9 4.3  3.3 (0.3)  3.2 (1.0)  3.8 (0.2) YIELD% ELONGATION AT 2.2 6.2  4.6 (1.0) 10.7 (6.0) 16.8 (3.0) BREAK % IMPACTkJ/m2 42.5 >100 70.8 (19)  >100 >100 Un-notched IMPACT kJ/m2 7.8 13.410.7 (1.2) 14.0 (1.6) 14.3 (1.7) notched

D. Publications

The disclosures of the publications, patents, and published patentspecifications referenced below are hereby incorporated by referenceinto the present disclosure in their entirety.

-   Baly, E. C. C. et al. (1939), Trans. Faraday Soc., Vol. 35, pp.    1165-1175.-   Barr, J. (1907), French Patent 377,086.-   Bartuska, M. and Kalina, J. (1968a), Czech. Patent 128,699.-   Bartuska, M. and Kalina, J. (1968b), Czech. Patent 128,894.-   Bradley, T. G. and McAdam, R. L. (1979), U.S. Pat. No. 4,134,857.-   Breese, R. (1994), in Industrial Minerals and Rocks, 6th ed.,    (Littleton, Colo.: Society for Mining, Metallurgy, and Exploration);    pp. 397-412.-   Bregar, G. W. (1955), U.S. Pat. No. 2,701,240.-   Brozek, M. et al. (1992), Przegl. Gorn., Vol. 48, No. 7, pp. 16-20.-   Cai, H. et al. (1992), Kuangchan Zonghe Liyong. (1992), No. 6, pp.    1-8.-   Codolini, L. (1953), Italian Patent 487,158.-   Dufour, P. (1990), French Patent 9,007,690.-   Dufour, P. (1993), U.S. Pat. No. 5,179,062.-   Engh, K. R. (1994), in Kirk-Othmer Encyclopedia of Chemical    Technology, 4th ed., vol. 8 (New York: John Wiley & Sons); pp.    108-118.-   Filho, F. X. H. et al. (1980), Mineraca Metalurgia Vol. 44, No. 424,    pp. 14-21.-   Gruder, G. et al. (1958), Rev. Chim. (Bucharest), Vol. 9, pp.    361-366.-   Hermanson, G. T. et al. (1992), Immobilized Affinity Ligand    Techniques (San Diego: Academic Press Inc.).-   Hessling, G. (2004), Conference Proceedings of the 17th Industrial    Minerals International Congress.-   Heyse, K. U. et al. (1980), Brauwissenschaft, Vol. 33, pp. 137-143.-   Koech, R. (1927), German Patent 469,606.-   Leeds and Northrup (1993, North Wales, Pa.), Microtrac® X-100 &    SRA150 Operator's Manual 179551, Rev. B.-   Li, F. (1990), Feijinshukang, Vol. 1989, No. 3, pp. 27-28 and 43.-   Liang, C., et al. (1990), Chinese Patent 1,044,233.-   Marcus, D. et al. (1964), Rev. Chim. (Bucharest), Vol. 15, No. 11,    pp. 671-674.-   Marcus, D. (1967), Rev. Chim. (Bucharest), Vol. 18, No. 6, pp.    332-335.-   Martin, C. C. and Goodbue, D. T. (1968), U.S. Pat. No. 3,375,922.-   Mitsui, Y., et al. (1989), Japanese Patent 01-153564.-   Moreland, J. E. (1975), U.S. Pat. No. 3,915,735.-   Munn, D. R. (1970), U.S. Pat. No. 3,547,260.-   Nielsen, R. B. and Vogelsang, C. J. (1979), U.S. Pat. No. 4,142,968.-   Nishimura, Y. (1958), Japanese Patent 4,414.-   Norman, J., et al. (1940), Mining Technology May 1940, pp. 1-11.-   Pesce, L. (1955), Italian Patent 529,036.-   Pesce, L. (1959), German Patent 1,052,964-   Sample, T. E., Jr. and Horn, J. M. (1981), U.S. Pat. No. 4,260,498.-   Suzuki, T., and Tomizawa, T. (1971), Japanese Patent 46-7563.-   Swallen, L. C. (1950), U.S. Pat. No. 2,504,347.-   Tarhanic, L. et al. (1979), Geol. Pruzkum Vol. 21, No. 5, pp.    140-142.-   Shiuh, J. C. et al. (1997), U.S. Pat. No. 5,656,568.-   Shiuh, J. C. et al. (2003), U.S. Pat. No. 6,653,255.-   Smith, T. R. (1991a), U.S. Pat. No. 5,009,906.-   Smith, T. R. (1991b), Canadian Patent 2,044,868.-   Smith, T. R. (1991c), Danish Patent 9,101,179.-   Smith, T. R. (1992a), German Patent 4,120,242.-   Smith, T. R. (1992b), Dutch Patent 9,101,957.-   Smith, T. R. (1992c), Brazilian Patent 9,102,509.-   Smith, T. R. (1993), Australian Patent 638,655.-   Smith, T. R. (1994a), U.K. Patent 2,245,265.-   Smith, T. R. (1994b), Japanese Patent 6-315368.-   Schuetz, C. C. (1935), U.S. Pat. No. 1,992,547.-   Thomson, W. and Barr. J. (1907), U.K. Patent 5397.-   Vereinigte Stahlwerke A.-G. (1931), U.K. Patent 341,060.-   Visman, J., and Picard, J. L. (1972), Canadian Patent 890,249.-   Videnov, N. et al. (1993), Inter. J. Miner. Process., Vol. 39, pp.    291-298.-   Wang, S. (1992), Feijinshukang, Vol. 1992, No. 3, pp. 10-13.-   Xiao, S. (1986), Chinese Application 86-107500.-   Zhong, S., et al. (1991), Chinese Patent 1,053,564.

Having now described the invention in detail as required by the patentstatutes, those skilled in the art will recognize modifications andsubstitutions to the specific embodiments disclosed herein. Suchmodifications are within the scope and intent of the present inventionas defined in the following claims.

1. A new functional additive in polymers comprising micronized diatomitehaving a median particle size less than 10 microns and a top particlesize less than 20 microns.
 2. The new functional additive in polymers ofclaim 1, wherein the median particle size is less than 8 microns and atop particle size less than 18 microns.
 3. The new functional additivein polymers of claim 2, wherein the median particle size is less than 6microns and a top particle size less than 16 microns.
 4. The newfunctional additive in polymers of claim 3, wherein the median particlesize is less than 4 microns and a top particle size less than 13microns.
 5. The new functional additive in polymers of claim 4, whereinthe median particle size is less than 3 microns and a top particle sizeless than 10 microns.
 6. The new functional additive in polymers ofclaim 1, wherein the additive has a blue light brightness greater than80.
 7. The new functional additive in polymers of claim 6, wherein theadditive has a blue light brightness greater than
 82. 8. The newfunctional additive in polymers of claim 7, wherein the additive has ablue light brightness greater than
 84. 9. The new functional additive inpolymers of claim 8, wherein the additive has a blue light brightnessgreater than
 86. 10. The new functional additive in polymers of claim 9,wherein the additive has a blue light brightness greater than
 88. 11.The new functional additive in polymers of claim 10, wherein theadditive has a blue light brightness greater than
 90. 12. The newfunctional additive in polymers of claim 1, wherein the additive hasreinforcing effect in thermoset plastics.
 13. The new functionaladditive in polymers of claim 1, wherein the additive has reinforcingeffect in thermoplastic materials.
 14. The new functional additive inpolymers of claim 13, wherein the additive has reinforcing effect inNylon.
 15. The new functional additive in polymers of claim 14, whereinthe surface of the additive is modified with gamma-aminopropyltriethoxysilane.
 16. The new functional additive in polymers of claim 1, whereinthe additive can be used as functional filler in paints, coatings andpapers.
 17. A process for the preparation of the new functional additivein polymers of claim 1, the method comprising using a stirred mediamill, thereby to obtain the new functional additive in polymers.
 18. Aprocess for the preparation of the new functional additive in polymersof claim 1, the method comprising using a ball mill, thereby to obtainthe new functional additive in polymers.
 19. A process for thepreparation of the new functional additive in polymers of claim 1, themethod comprising using a combination of a ball mill combined with anair classifier, thereby to obtain the new functional additive inpolymers.
 20. A process for the preparation of the new functionaladditive in polymers of claim 1, the method comprising using an air jetmill, thereby to obtain new functional additive in polymers.
 21. Aprocess for the preparation of the new functional additive in polymersof claim 1, the method comprising using a Mikro-ACM® air classifyingmill, thereby to obtain the new functional additive in polymers.
 22. Aprocess for the preparation of the new functional additive in polymersof claim 1, the method comprising using an “in-situ” addition of silane,thereby to obtain the surface modified new functional additive inpolymers.
 23. The new functional additive in polymers of claim 1 whereinthe surface of the additive is modified by silanization.
 24. The newfunctional additive in polymers of claim 23 wherein the silanizationincreases the hydrophobic properties of the additive.
 25. The newfunctional additive in polymers of claim 24 wherein the silanizationcomprises modifying the additive with Dimethyldichlorosilane.
 26. Thenew functional additive in polymers of claim 24 wherein the silanizationcomprises modifying the additive with Hexadimethylsilazane.
 27. The newfunctional additive in polymers of claim 23 wherein the silanizationincreases the hydrophilic properties of the additive.
 28. The newfunctional additive in polymers of claim 27 wherein the silanizationcomprises modifying the additive with aminopropyltriethoxysilane. 29.The new functional additive in polymers of claim 23 wherein the surfaceof the additive is etched prior to silanization.
 30. The new functionaladditive in polymers of claim 29 wherein an etchant is selected from thegroup consisting of hydrofluoric acid, ammonium bifluoride, sodiumhydroxide, fluorine, ammonia, ammonium hydroxide, and phosphoric acid.31. The new functional additive in polymers of claim 23 wherein thesilanization coating is about 2 to about 3 percent by weight.